The present invention relates to an apparatus for controlling a gas flow to a receiving unit from a pressurized gas source and it finds a particularly important application in the aeronautic field where such control devices are used to supply the crew members of fighter aircraft with a breathing mixture of appropriate composition and pressure and to supply gas inflating a high altitude or g-suit for avoiding distension of the rib cage if a pressurized breathing mixture is inhaled or for obviating the effects of acceleration.
At the present time, the devices or regulators for the above-mentioned applications are purely pneumatic in operation; they are consequently bulky, their characteristics are practically frozen and their response times are sometimes excessive.
It is an object of the invention to provide an improved apparatus which has a shorter response time and may be quite compact in design.
According to an aspect of the invention, there is provided an apparatus for regulating the gas flow to a receiving unit from a pressurized gas source, comprising a gas control device having a servo valve piloted by a solenoid valve which has two positions only and is controlled by computer means connected to receive input data from sensors carried by said device, in accordance with a stored program.
Due to the use of electronic components, the response time may be extremely low and may even approach a millisecond. The consumption may be very low, since balanced solenoid valves may be constructed requiring a control power less than 1 watt.
A pressure balanced valve suitable for use with high inlet pressure is described in copending U.S. patent application No. 145,841 for "Apparatus for creating gas flow cycles" of the Applicants.
A demand breathing regulator for use with a mask according to a first embodiment of the invention comprises a housing, a piloted main valve in the housing controlling communication between a source and a breathing mask, a pilot diaphragm subjected to the pressure in the mask, a pressure sensor in the mask, a solenoid valve for controlling communication between a control chamber for the main valve and a pressure relief outlet and electronic computer means controlling the solenoid valve responsive to the signals supplied by the sensor.
A g-valve, forming another embodiment of the invention, comprises a housing defining a chamber arranged for connection with a g-suit, fitted with a pressure sensor, a pressurized gas inlet electromagnetic valve in the chamber and an exhaust valve driven by the pressure in a control compartment connected by a calibrated leakage orifice to the chamber and by an electromagnetic valve to the atmosphere, and computing means receiving the signals from the pressure sensor and from an acceleration sensor supported by the case and controlling the electromagnetic valve as a function of the signals received.
The breathing regulator and the anti g-valve may be combined in a single unit; in addition to the above-defined functions, that unit may fulfil the functions of pressurizing the breathing mixture when the crew is subjected to acceleration and/or pre-inflating pockets of the g-suit at high altitude. These functions are fulfilled by a purely pneumatic installation in the system of French Pat. No. 77 20345.
The invention will be better understood from the following description of control devices which form particular embodiments thereof, given by way of examples.